The land plant-specific MIXTA-MYB lineage is implicated in the early evolution of the plant cuticle and the colonization of land.


Type
Article
Change log
Abstract

The evolution of a lipid-based cuticle on aerial plant surfaces that protects against dehydration is considered a fundamental innovation in the colonization of the land by the green plants. However, key evolutionary steps in the early regulation of cuticle synthesis are still poorly understood, owing to limited studies in early-diverging land plant lineages. Here, we characterize a land plant specific subgroup 9 R2R3 MYB transcription factor MpSBG9, in the early-diverging land plant model Marchantia polymorpha, that is homologous to MIXTA proteins in vascular plants. The MpSBG9 functions as a key regulator of cuticle biosynthesis by preferentially regulating expression of orthologous genes for cutin formation, but not wax biosynthesis genes. The MpSBG9 also promotes the formation of papillate cells on the adaxial surface of M. polymorpha, which is consisitent with its canonical role in vascular plants. Our observations imply conserved MYB transcriptional regulation in the control of the cutin biosynthesis pathway as a core genetic network in the common ancestor of all land plants, implicating the land plant-specific MIXTA MYB lineage in the early origin and evolution of the cuticle.

Description
Keywords
MIXTA, MYB transcription factor, cuticle biosynthesis, evolution, papillate cells, plant terrestrialisation, regulatory network, Embryophyta, Gene Expression Regulation, Plant, Gene Regulatory Networks, Marchantia, Phylogeny, Plant Proteins, Transcription Factors
Journal Title
New Phytol
Conference Name
Journal ISSN
0028-646X
1469-8137
Volume Title
229
Publisher
Wiley
Rights
All rights reserved
Sponsorship
Natural Environment Research Council (NE/K009303/1)